Abstract: To strengthen the capacity for disaster prevention and mitigation, overcome the prediction errors of strong convection process. We analyzed a mixed strong convective event in south-central Zhejiang on June 29, 2018 based on multi-source meteorological observation data. The results showed that: the forward trough, surface convergence line and orographic uplift led to the development and maintenance of new convection; the accumulation of unstable energy in the early stage was obvious; high Cape, θse energy cumulation zone and 925 hPa specific humidity had good indicative significance for this strong convection intensity; but the inversion layer and dry intrusion led to poor reference of K; 9 body sweeps and strong wind shear occurred in the mesocyclone during hailstorm; at the same time, the jump of VIL was 18 min ahead of the hail time providing early warning time for short-term forecast; high sensitivity of ρVIL was showed in this process, and combining the estimation of hail diameter (≥5) and VIL (≥4) could provide the better significance; the combination of VIL with VILmax and ρVILmax could deduce the property of the storm; the offsetting effect of storm bearing layer resulted in the limited development of the hailstorm.